Precision orbit determination research of LEO satellite simulated downlink data

This study focuses on precision orbit determination utilizing simulated downlink data from low earth orbit (LEO) satellites. A comprehensive investigation is conducted on the orbit determination performance, considering a simulated Walker 90/10/1 LEO satellite constellation with an orbit altitude of 1 000 km and an inclination angle of 48°, along with 150 ground stations equipped with corresponding orbit clocks and observation data. The observational data from global station networks, featuring station numbers ranging from 60 to 150, are utilized for precise orbit determination of LEO satellites, followed by a detailed analysis of orbit accuracy and station position dilution of precision (SPDOP) values. Results indicate a significant enhancement in LEO satellite orbit accuracy from 117.5 mm to 39.8 mm upon increasing the number of stations from 60 to 150. Furthermore, sparse station distribution leads to a rapid degradation in LEO satellite orbit accuracy. The study underscores the effectiveness of augmenting the number of ground stations in improving both visible station SPDOP and LEO satellite orbit accuracy over terrestrial regions. However, due to the constrained tracking range of stations, enhancing the orbit accuracy of LEO satellites in marine regions remains challenging.